BEAUMONT, Texas — A Texas appeals court has sent to arbitration a dispute in which Exxon is seeking coverage as an additional insured for a 2013 fatal refinery fire, ruling that the insurer has the right to enforce the policy’s arbitration agreement because Exxon’s claims are based upon the policy.

On April 27, the Texas Court of Appeals, 9th District, further held that the dispute falls within the ambit of the arbitration clause because it involves a disagreement over the interpretation of the policy’s “additional insured” clause.

In April 2013, a fire occurred at Exxon’s Beaumont, Texas refinery, during which ...